Simple Drawings: Fast, Accurate Figure Matching
What is being tested
Simple Drawings measures how quickly and accurately you can decide whether two line drawings show the same object. You are given a target drawing and several choices; typically only one choice is the target turned to a new orientation, while the rest are altered or mirrored.
Concepts to master
- Rotation is allowed; reflection is not. A figure spun 90, 180, or 270 degrees is still the same figure. A flipped (mirror-image) version is a different figure, even when it looks familiar.
- Feature hierarchy. Every drawing has one or two distinctive landmarks: an acute corner, a long straight segment, a small notch, a point where lines cross. Compare landmarks first, not overall shape feel.
- Proportional change. Wrong choices often keep the outline but lengthen one segment or open one angle slightly. These read as close enough at a glance and are the most common trap.
- Chirality traps. If a hook opens right in the target and left in a choice, that choice is a mirror image; reject it even when everything else matches.
Method
Anchor one landmark on the target, then check that same landmark on each choice in a fixed order. Confirm a second landmark before committing. If two choices survive, compare segment lengths and angles to break the tie. Do not over-invest in a single item; unanswered items cost more than quick, reasonable guesses.
Worked example
Target: an L-shaped bracket with a short arm pointing up and a long arm pointing right, with a notch on the long arm's outer edge. A choice shows the same bracket with the long arm pointing down and the notch still on the outer edge; that is a 90 degree rotation, so it is correct. A choice with the long arm pointing left and the notch on the inner edge is both a reflection and an alteration; reject it.